After its discovery in 2006, DNA origami approach has been exploited to fabricate a wide range of 2D and 3D DNA nanostructures. Such nanostructures have been extensively used in many applications including nanorobotics, molecular computation, and drug delivery. However, the biosensing applications of the DNA origami structures have not been explored well. Compared to conventional carbon or metal based substrates for nanoassembly, DNA origami nanostructures provide a biocompatible environment, suitable for many biological reactions. In addition, the chemical components of the origami-based DNA nanostructures are precisely known and can be well controlled at any location, which allow a facile modification and ready incorporation of functional components in the 2D or 3D nanoassembly. These properties render DNA origami an outstanding platform for high throughput and multiplex biosensing.
The present inventors have previously developed a first-in-class biosensing mechanism that employs mechanochemistry principles to detect single-nucleotide polymorphism in DNA sequences. Mechanochemistry is an emerging discipline that deals with the coupling of mechanical and chemical processes. Under mechanical stress, the stability of covalent or non-covalent bonds changes, which either strengthens or weakens molecular structures. In mechanochemical sensing, the binding affinity between a receptor-ligand complex changes mechanical tension of either a free receptor or substrate. To serve as an effective mechanochemical sensor, therefore, the signal transduction unit must exploit mechanical signals, such as mechanical work, tension in a recognition template, or pressure in a system. Since the force signal experiences little environmental interference, the mechanochemical sensor has an advantage of high signal-to-noise ratio. The mechanochemical coupling employed in this type of sensor gives rise to a change in the mechanical property of a template as it recognizes a target through chemical interactions. Therefore, target recognition and signal transduction units in a traditional sensor can be integrated. This not only simplifies the sensing scheme, but also improves the performance of the sensor, since noise present in extra components of a sensing scheme can be avoided.
Due to the superior property of force and spatial resolutions, optical tweezers are an ideal tool used for mechanochemical sensing. However, the throughput of the sensing is low since each time only one template can be investigated. Thus, a problem of the invention was to develop high throughput mechanochemical sensing platforms and sensing methods.